The 'corrugator supercilii' is a small, narrow, pyramidal muscle close to the eye. It is located at the medial end of the eyebrow, beneath the frontalis muscle (muscle which covers parts of forehead of the skull) and just above orbicularis oculi muscle (muscle in the face that closes the eyelids).

The corrugator draws the eyebrow downward and medially, producing the vertical wrinkles of the forehead. It is the "frowning" muscle, and may be regarded as the principal muscle in the expression of suffering. It also contracts to prevent high sun glare, pulling the eyebrows toward the bridge of the nose, making a roof over the area above the middle corner of the eye and typical forehead furrows.

The muscle is sometimes surgically severed or paralysed with botulinum toxin as a preventive treatment for some types of migraine or for aesthetic reasons.

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